In brief
In Rajab of 2 AH, the Prophet ﷺ sent eight of the emigrants from Makkah under his cousin Abdullah ibn Jahsh, with a sealed letter to be opened only after two days of travel. It sent them to Nakhla, a grove of date palms outside Makkah, to watch the movements of the Quraysh. On the way, two of the men stayed behind to search for a lost camel. The other six reached Nakhla on the last day of Rajab, a sacred month in which fighting was forbidden, and found a small Quraysh trade caravan guarded by only three men. With the month about to end and the caravan about to slip away, they attacked, killing one man and taking two prisoners. Back in Madinah the Prophet ﷺ told them he had not commanded them to fight and refused the booty, while the Quraysh spread word across Arabia that the Muslims had shed blood in a sacred month. Allah then revealed Qur'an 2:217. It agreed that fighting in the sacred month was a grave sin, but declared that driving the believers out of Makkah and barring the way to the Sacred Mosque was worse. The Prophet ﷺ then accepted the booty and the prisoners, and released the prisoners for ransom once the two missing men had returned safely.
Outcome: Both prisoners were ransomed and released. One of them, al-Hakam ibn Kaisan, accepted Islam once his ransom had been paid.
This was the first expedition in which the Muslims took captives and booty. It was also the occasion for the revelation of Qur'an 2:217, about fighting in the sacred months. One of the two prisoners, al-Hakam ibn Kaisan, accepted Islam once his ransom had been paid. He was the first of many prisoners in later battles who became Muslim only after their ransom reached the Prophet ﷺ, so that the money would be in his hands.
Other events recorded in 2 AH. Their order within the year is not established; use the storyline above for the sequence.
Now a Muslim: I embraced Islam only after my ransom reached the Prophet ﷺ, so that the wealth would remain in his hands.
You go ahead: leave us in the desert, and we will find our camel; the expedition must go on.
When this letter of mine is read to you, proceed to Nakhla. Watch the movement of the Quraysh and inform us of their preparations and actions. Do not force any of your companions to go: whoever wants to come back can come back.
Whoever wants shahada and is eager to meet Allah, let him come with me. And whoever doesn't may go back to Madinah. But as for me, I am going to proceed onwards to Makkah.
We will not release these two prisoners until our two companions reach us safely.
The two prisoners were the Quraysh caravaneers captured at Nakhla; the two companions were Sa'd ibn Abi Waqqas and Utbah ibn Ghazwan, who had fallen behind on the outward journey searching for their lost camel.
I didn't command you to fight.
Said to the Nakhla party on their return, after they had killed a caravaneer and taken captives during the Sacred Month of Rajab, though the Prophet ﷺ had sent them only to gather information.
يَسْـَٔلُونَكَ عَنِ ٱلشَّهْرِ ٱلْحَرَامِ قِتَالٍۢ فِيهِ ۖ قُلْ قِتَالٌۭ فِيهِ كَبِيرٌۭ ۖ وَصَدٌّ عَن سَبِيلِ ٱللَّهِ وَكُفْرٌۢ بِهِۦ وَٱلْمَسْجِدِ ٱلْحَرَامِ وَإِخْرَاجُ أَهْلِهِۦ مِنْهُ أَكْبَرُ عِندَ ٱللَّهِ ۚ وَٱلْفِتْنَةُ أَكْبَرُ مِنَ ٱلْقَتْلِ
“They ask you about the Sacred Month — about fighting therein. Say, 'Fighting therein is great [sin], but averting [people] from the Way of Allah and disbelief in Him and [preventing access to] al-Masjid al-Haram and the expulsion of its people therefrom are greater [evil] in the Sight of Allah. And fitna is greater [evil] than killing...'”
Revealed regarding the killing during the Sariyya Nakhla, which took place on the last day of the sacred month of Rajab.